This invention relates in general to an improved wire rope and more particularly relates to an improved small diameter wire rope with a ductile metal core.
Within the wire rope industry there is a class of relatively small diameter products that are known by the term "aircraft cable". The term probably was chosen at a time when strong small diameter wire rope was developed for a wide number of applications in aircraft for controls and for bracing and the like. Such wire rope continues to be used in such applications and additionally aircraft cable finds many other uses such as in yacht rigging, small hoists, tie rods, machine parts and slings. In many applications it is used as a security device with swaged fittings completing a closed loop which is tamper resistant.
Usual aircraft cable type wire rope runs from about 1/32 to 11/2 inch in diameter and is comprised of seven strands heliacally arranged about a wire strand core. Each strand is made up of multiple wires (typically 7 thru 41 wires) which may be high strength regular, tinned, galvanized or stainless steel. Also the wire rope may be lubricated or non-lubricated depending on bending and corrosion service conditions. The cables and particularly the outer strands have been formed of relatively high carbon content steel wire (typically 0.6%-0.8% Carbon) having a high resistance to abrasion and bending fatigue and a high tensile strength.
The latter qualities however involve high material cost and result in wire rope that is relatively weak to shearing forces (and therefore is relatively easily cut) and tends to restraighten when bent and released. Yet in many applications, particularly those involving safety and security uses, it is desirable that the wire rope be resistant to shear and able to retain a bent shape.